There exists a number of inline dispensers for use in water systems and, particularly inline water systems, which are used for treating pool and spa water as well as other types of water suitable for a variety of purposes. One of the difficulties of using such systems is that the systems generally have limited capacity and limited dispersants and consequently limited control of water quality. Since such inline systems are usually an integral part of a circulation system it can become costly to upgrade or change the system in order to improve or increase the capacity or the performance of the water treatment system. The invention described herein allows a person to enhance and increase the performance of a water treatment system as well as expand the performance of the water treatment system without having to remove or replace integral components of an existing inline dispensing system.